No Weld of mine ever failed, but i have made repairs i had to make a note of needing to be redone ASAP.
For instance a chemical tanker i sailed on, the pump assembly that was down in the stainless steel tank just where the pipe pick up the highly flammable / explosive stuff, had shaken loose and snapped several 15 mm thick stainless steel support brackets, and all i had for welding in stainless was arch welding electrodes with a 1.5 mm core, where for a job like that a 3.25 mm core would have been much more it.
But i managed to get the things to stick together in spite of it was actually only my #2 time welding in stainless steel with a arc welder, and the #1 time was a travesty so i had to get a more experienced welder to do it for me as it was just 2 pieces of thin sheet needing to be tacked together.
I do like arc welding, and was pretty good at it as a apprentice, TIG / MIG & MAG is okay too as well as oxy / acetylene welding, just not as challenging IMO.
As a apprentice on trade school we had a 2 weeks of arc and oxy / acetylene welding, i did all my work in 2 days, TIG / MIG & MAG was not on the books at all, bud i did do a lot of MAG on trains.
A good looking welding can almost make me exited